Preheat your oven to 375°F and lightly grease a small oven-safe baking dish.
Bring a pot of salted water to a boil and cook the whole wheat ziti until just al dente, then drain and set aside.
In a large skillet over medium heat, sauté the diced yellow onion and minced garlic until the onion is translucent and fragrant.
Add the ground turkey to the skillet, breaking it up with a spatula, and cook until browned and no longer pink.
Stir in the fresh spinach and cook for 1-2 minutes until completely wilted.
Pour in the marinara sauce, dried oregano, sea salt, and black pepper, simmering the mixture for 3 minutes to meld the flavors.
Add the cooked ziti to the skillet and toss thoroughly to ensure the pasta is well-coated with the meat sauce.
Transfer the pasta mixture into the prepared baking dish, spreading it out into an even layer.
Dollop the part-skim ricotta cheese over the top of the pasta and sprinkle evenly with the shredded mozzarella cheese.
Bake in the oven for 15 to 20 minutes until the cheese is melted and the sauce is bubbling at the edges.
Remove from the oven and let rest for 5 minutes before garnishing with freshly chopped basil and serving.